At first glance, Terminal looks like it still needs some level of integration and development work. It's not a ready-to-go, install-the-app-and-process-payments solution.

Terminal is really for people like this guy. For folks who want to sell/distribute integrated POS systems e.g. Shopify.

That’s exactly right. Terminal solved a problem for me (I used to integrate Mattel card readers to a serious amount of pain). I worked with Stripe to help identify good ones, and they built easy to use APIs to integrate. This is exactly what they hoped for.

I think terminal is largely targeted at bigger businesses, where as this product is more like Square, targeted at small independent businesses and shops.

Honestly, it sounds like the OP is doing a great job at sales, and he's just making money as an underpaid affiliate.

The key is that he's not even an affiliate. His cut is coming from his customer, not from Stripe (he charges 1% on top of what Stripe charges the user). Therefore Stripe doesn't have a financial reason to build this app, they already collect the same fees from these users.

That's just one more thing to carry. If you have the option of just using your phone, what are you going to pick?